Video games have become very popular family entertainment. In order to play a video game, a game cassette is first installed in a video game machine body. Game data, contained in the cassette and including video information or video plus audio information, is read out and output to a common television receiver. Accordingly, the one who wishes to play a video game must have a video game machine and a game cassette, besides his television set. Once he installed the game cassette containing the game he chose to play, he can play the game whenever and as many times as he wishes.
However, there lies a problem: the player has to purchase each and every game cassette he wishes to play, which is very costly. For all the advantage that the player can play the game repeatedly, he may soon get tired of the game, or the game content may not be oriented for repeated play.
Another entertainment increasing in popularity is "karaoke", i.e. singing to recorded instrumental accompaniment. More and more "karaoke bars" can be seen in major cities, and karaoke apparatus for domestic use are also widely accepted. Such a family karaoke apparatus needs, by definition, karaoke music software among various forms of software available in the marketplace, such as video disk and video tape containing video plus audio information, or music tape containing only audio information. The karaoke singers, tempted by changes in the update music trend, tend to purchase newly available karaoke data one after another. There arise problems of accumulated expenditure and limited storage space for the increasing software.